Printing plate cylinder



y 24, 1955 c. A. HARLESS PRINTING PLATE CYLINDER 2 Shee ts-Sheet 1 Filed May 31, 1952v INVEN T R. fi4ZI/esA.Har 3 BY ATTO M y 1955 c. A. HARLESS PRINTING PLATE CYLINDER 2 Sheets-Sheet 2 Filed May 51, 1952 INVENTOR (1201/98 AHar/ess BY 2 ATTOHAZYS United States Patent PRINTING PLATE CYLINDER Charles A. Harless, Riverside, C0nn., assignor to R. Hoe & Co., Inc., New York, N. Y., a corporation of New York Application May 31, 1952, Serial No. 290,940

8 Claims. (Cl. 101-378) This invention relates to improvements in printing plate cylinders, and more particularly in the means for fixing stereotype or similar printing plates to the cylinders.

The invention is concerned with cylinders of the type in which the plates are held by clips engaging underneath the plates for holding them on the cylinder. In such constructions, the use of the cylinder has been generally restricted to plates of a fixed and determined width, requiring extensive alterations to permit a change in the width of paper printed. The manufacture of cylinders has also been expensive due to the need for manufacture of different holding devices, and, in some cases, different machining of the cylinder body itself in order to produce a cylinder for the plate width desired by a particular customer.

It is an object of the invention to provide a cylinder structure in which the components may be standardized but combined together in various ways by mere assembly operations so as to be adapted for use with plates of any given width.

Another object of the invention is to provide a cylinder which is so constructed that a printer may readily rearrange the components to adapt the cylinder to print on papers of diiferent widths.

A cylinder embodying the invention in a preferred form will now be described with reference to the accompanying drawing, and the features forming the invention will then be pointed out in the appended claims.

In the drawing:

Figure 1 is a plan view of the printing cylinder of the invention; I

Figure 2 is a similar fragmentary plan view, showing the parts rearranged for holding plates of different width so as to permit printing on a narrower web;

Figure 3 is an end elevation of the cylinder of Figure 1;

Figure 4 is an enlarged section on the line IV-IV of Figure 1; and

Figures 5 and 6 are sections on a somewhat smaller scale, taken on the respective lines V-V and VIVI of Figure 4, and an operating cam shaft being omitted to show the clamping assembly structure more clearly.

The cylinder 1 carries a number of plates 2, the outlines of which are indicated in phantom in Figure 1. As usual, the cylinder illustrated may carry a total of eight plates, arranged four across and two around the cylinder, and the plates at one end of the cylinder being staggered or angularly displaced with reference to the plates at the other end of the cylinder, for reducing vibration in printing.

A number of plate clamp units 3 and spacer blocks 4 are provided, and the plate clamp units are operated in groups of four by means of .shafts 5 having square heads protruding from the ends of the cylinder to permit turning of the shafts with a wrench.

The cylinder is provided with generally rectangular axial grooves or channels 7 having axial dovetail holding grooves 8 formed in their radially inward and bottom surfaces. Bores 9 (Figure 4) communicating with the channels 7 to one side thereof, accommodate the operating shafts 5.

As shown in detail in Figures 4, 5 and 6, each clamping unit 3 comprises a generally rectangular block 10 fitting within a groove 7, and held therein by means of bolts 11 engaging in dovetail shaped nuts 12 within the dovetail groove 8. The block is cut off to one side along the surface 13, continuing the wall of bore 9 and accommodating shaft 5. It is further cut out to receive the clamping hook members 14, which are rotatably or pivotally mounted on a pin or shaft 15, carried within an axial bore through the body 10. Each of the hooks 14 is recessed, as indicated, to take a roller 16 rotatably carried by the hook by means of a pin or shaft 17. The hooks are urged away from clamping position (toward the phantom position of Figure 4) by means of plungers 18 carried in bores in the block 10 and urged toward the hooks by means of springs 19. The operating shaft 5 is formed as a continuous cam, so that a clamping unit may be placed in any location along the cylinder and the rollers 16 may still operably engage the shaft.

In the full line position of Figure 4, the cam shaft is indicated as having been turned (clockwise in the figure) to bring its high dwell 20 against the roller 16, thus urging the hooks 14 into clamping engagement in the clamping recesses provided on the inner surface of the plates. Rotating the shaft 5 (counterclockwise from the position shown), permits the spring pressed plungers 18 to force the hooks rearwardly, so that they ultimately reach the phantom position of Figure 4, in which the rollers are against a low dwell 21 of the cam shaft.

The block 10 is also cut out to receive a clamping block 22, held therein as by means of screws 23 and provided with hooks 24 for engaging in the clamping recesses under the second set of plates carried by the cylinder. Thearrangement of Figure 4 being duplicated symmetrically around the cylinder, it will be apparent that each plate is held securely to the cylinder by a set of hooks 14 at one end and hooks 24 at the other. Since the construction is radially symmetrical, the dynamic balance of the cylinder is preserved.

In Figure l, the clamping units 3 are shown as separated by spacing elements 4 so as to locate them for printing on a relatively wide web, as, for example, a 66 inch web. In Figure 2, the clamping units 3 are shown as butting together, with the filler blocks 4 placed at the end of groove 7, for accommodating the narrowest width web provided for, which might be, for example, a 56 inch web. The end block 4 occupies the same position in any case and may be formed with a shoulder 4 (Figures 3 and 6) for engaging a shoulder near the outer end of the shaft 5 for holding the shaft in the bore 9. In relocating the clamping assemblies, it is necessary only to turn the cylinder into a position where the blocks 4 and clamping assemblies 3 may he slid in and out of the groove without interference with adjacent frames or other structures.

In manufacturing cylinders according to the invention, a number of cylinder bodies may be formed simultaneously and identically, by machining out the grooves 7 and forming the bores 9 and dovetail grooves 3. The construction being standardized, the utmost precision can readily be obtained at low unit cost, the required jigs, tools and gauges being useable over and over again in the production of a very large number of cylinders. So also, since the units 3, shafts 5 and filler pieces 4 are standardized, similar economy of production is ob tained. It also becomes possible to materially reduce set up time per part, by manufacturing any of the components in such quantities as may be convenient from time to time. The blocks 10 and filler pieces 4 may J be ground together with the cylinder in which they are to fit or may be ground separately.

What is claimed is:

l. A plate cylinder for printing presses, comprising a cylinder body having an axially extending groove for accommodating plate clamping mechanisms, a plurality of plate clamping assemblies fitting in and slidable along the said groove, each plate clamping assembly comprising plate engaging members movable circumferentially within the said groove for clamping and releasing a plate by engaging in recesses underneath the plate and ad}; at a straight edge thereof and also comprising oppositely facing members for engaging in recesses under another plate edge, means fixing the plate clamping assemblies in the groove, and means carried by the cylinder for operating the said plate engaging members.

2. A plate cylinder for printing presses, comprising a cylinder body having an axially extending groove for accommodating plate clamping mechanisms, a plurality of plate clamping assemblies fitting in and slidable along the said groove, each plate clamping assembly comprising plate engaging members movable circumferentially within the said groove for clamping and releasing a plate by engaging in recesses underneath the plate and adjacent a straight edge thereof and also comprising oppositely facing members for engaging in recesses under another plate edge, spacer blocks also fitting in and slidable along the groove, means for fixing the plate clamping assemblies and spacer blocks in the groove in end-toend abutting relation, and means carried by the cylinder for operating the said plate engaging members.

3. A plate cylinder for printing presses, comprising a cylinder body having an axially extending groove for accommodating plate clamping mechanisms, a plurality of plate clamping assemblies fitting in and slidable along the said groove, each plate clamping assembly comprising plate engaging members movable circumferentially within the said groove for clamping and releasing a plate by engaging in recesses underneath the plate and adjacent a straight edge thereof and also comprising oppositely facing members for engaging in recesses under another plate edge, the cylinder having a further axial un-- dercut groove in the bottom of the first said groove, and the plate clamping assemblies including screws and cooperating nut members slidable in the undercut groove for fixing the plate clamping assemblies in position, and means carried by the cylinder for operating the said plate engaging members.

4. A plate cylinder for printing presses, comprising a cylinder body having an axially extending groove for accommodating plate clamping mechanisms, a plurality of plate clamping assemblies fitting in and slidable along the said groove, each plate clamping assembly comprising plate engaging members movable circumferentially within the said groove for clamping and releasing a plate by engaging in recesses underneath the plate and adjacent a straight edge thereof and also comprising oppositcly facing members for engaging in recesses under another platc edge, spacer blocks also fitting in and slidable along the groove, the cylinder having a further axial undercut groove in the bottom of the first said groove, and the plate clamping assemblies and spacer blocks includ ing screws and cooperating nut members slidable in the undercut groove and fixing the plate clamping assentill blies and spacer blocks in end to end abutting position, and means carried by the cylinder for operating the said plate engaging members.

5. A plate cylinder for printing presses, comprising a cylinder body having an axially extending groove for accommodating plate clamping mechanisms, a plurality of plate clamping assemblies fitting in and slidable along the said groove and comprising plate engaging members movable within the said groove for clamping and releasing a plate and cam followers for moving the said members, means fixing the plate clamping assemblies in the groove, and an operating shaft rotatably carried by the cylinder for operating the said plate engaging members, the said shaft comprising alength of continuous camshaped cross-section extending along the groove in position to operate the cam followers of an assembly in any position along the groove.

6. in a plate cylinder for a printing machine, a cylinder body having an axially extending channel in its periphery and a plurality of plate clamping units in the channel, the plate clamping units having plate clamping hooks formed to engage in recesses in the underside of a printing plate when the plate is mounted on the cylinder, a shaft rotatably supported in the channel and adjacent the plate clamping units, a cam surface on the shaft arranged to engage the plate clamping hooks and move them to effect the clamping of a plate, the said cam surface extending continuously in the axial direction to permit engagement of the plate clamping hooks thereby in a variety of axial positions of the said hooks.

7. in a plate cylinder for a printing machine, a cylinder body having an axially extending channel in its periphery and a plurality of plate clamping units in the channel, the plate clamping units having plate clamping J hooks formed to engage in recesses in the underside of a printing plate when the plate is mounted on the cylinder, a shaft rotatably supported in the channel and adjacent the plate clamping units, a cam surface on the shaft arranged to engage the plate clamping hooks and move them to effect the clamping of a plate, means on the shaft to receive a tool for rotating the shaft, and means for securing the clamping units in the channel with varying spacing between them, to position the hooks at suitable locations for both wide and narrow plates.

8. A plate cylinder for printing presses, comprising a cylinder body having an axially extending groove for accommodating plate clamping mechanisms, a plurality of plate clamping assemblies fitting in and slidable along the said groove and comprising plate engaging members movable within the said groove for clamping and releasing a plate, means for securing the plate clamping assemblies in the groove with a spacing that will locate a plate engaging member at a desired distance from each curved edge of the plate being used, and means carried by the cylinder for operating the said plate engaging members.

References Cited in the file of this patent UNITED STATES PATENTS 1,401,982 Hollingsworth Jan. 3, 1922 1,597,490 Storey Aug. 24, 1926 2,350,585 Carpenter June 6, 1944 2,506,845 Solomon May 9, 1950 

